Life Sciences Commons^™

Novel Aspects Of Drosophila Suzukii (Diptera: Drosophilidae) Biology And An Improved Method For Culturing This Invasive Species With A Modified D. Melanogaster Diet, Blair J. Sampson, Trevor Mallette, Karla M. Addesso, Oscar E. Liburd, Lindsy E. Iglesias, Stephen J. Stringer, Chris T. Werle, Donna A. Shaw, Drew Larsen, John J. Adamczyk

Agricultural and Environmental Sciences Faculty Research

Drosophila suzukii (Matsumara) (Diptera: Drosophilidae), the spotted wing drosophila, is a global pest of soft fruits now rearable on a standard D. melanogaster (Meigen) diet containing the fly's own natural food: soft-skinned berries. The techniques tested here can save 40% of cultures from microbial contamination that develops after combining artificial food sources (e.g., standard drosophila media) with unsterilized host plant material (berries). A suitable ratio for mixing dietary ingredients for a vial or test-tube rearing system includes, by weight, 1 part berry tissue for oviposition, 1.5 parts dry diet media for carbohydrate, 7 parts clean water for moisture, and ∼5 …

Broad-Sense Heritability And Genetic Gain For Powdery Mildew Resistance In Multiple Pseudo-F2 Populations Of Flowering Dogwoods (Cornus Florida L.), Lipi Parikh, Margaret T. Mmbaga, Srikanth Kodati, Matthew W. Blair, Dafeng Hui, Geoffrey Meru

Agricultural and Environmental Sciences Faculty Research

Powdery mildew caused by Erysiphe pulchra is one of the most destructive diseases of flowering dogwoods (Cornus florida L.). Control of powdery mildew relies heavily on chemical fungicides. Developing genetic resistance and planting powdery mildew resistant cultivars is a desirable long term control strategy for the disease. Information on inheritance characteristics associated with powdery mildew resistance in C. florida is needed to facilitate development of breeding strategies for a new generation of powdery mildew resistant cultivars. The objectives of this study were to determine broad-sense heritability, genetic gain and minimum number of effective genes associated with resistance to powdery mildew …

Exogenous Glutathione Improves High Root-Zone Temperature Tolerance By Modulating Photosynthesis, Antioxidant And Osmolytes Systems In Cucumber Seedlings, Xiaotao Ding, Yuping Jiang, Lizhong He, Qiang Zhou, Jizhu Yu, Dafeng Hui, Danfeng Huang

Biology Faculty Research

To investigate the physiological responses of plants to high root-zone temperature (HT, 35 °C) stress mitigated by exogenous glutathione (GSH), cucumber (Cucumis sativus L.) seedlings were exposed to HT with or without GSH treatment for 4 days and following with 4 days of recovery. Plant physiological variables, growth, and gene expression related to antioxidant enzymes and Calvin cycle were quantified. The results showed that HT significantly decreased GSH content, the ratio of reduced to oxidized glutathione (GSH/GSSG), chlorophyll content, photosynthesis and related gene expression, shoot height, stem diameter, as well as dry weight. The exogenous GSH treatment clearly lessened the …

Editorial: Food Legume Diversity And Legume Research Policies, Matthew W. Blair, Jing Wu, Shumin Wang

Agricultural and Environmental Sciences Faculty Research

No abstract provided.

Evaluation Of Common Bean (Phaseolus Vulgaris L.) Genotypes For Drought Stress Adaptation In Ethiopia, Kwabena Darkwa, Daniel Ambachew, Hussein Mohammed, Asrat Asfaw, Matthew W. Blair

Agricultural and Environmental Sciences Faculty Research

Drought stress linked with climate change is one of the major constraints faced by common bean farmers in Africa and elsewhere. Mitigating this constraint requires the selection of resilient varieties that withstand drought threats to common bean production. This study assessed the drought response of 64 small red-seeded genotypes of common bean grown in a lattice design replicated twice under contrasting moisture regimes, terminal drought stress and non-stress, in Ethiopia during the dry season from November 2014 to March 2015. Multiple plant traits associated with drought were assessed for their contribution to drought adaptation of the genotypes. Drought stress determined …

Qtl And Candidate Genes Associated With Common Bacterial Blight Resistance In The Common Bean Cultivar Longyundou 5 From China, Jifeng Zhu, Jing Wu, Lanfen Wang, Matthew W. Blair, Zhendong Zhu, Shumin Wang

Agricultural and Environmental Sciences Faculty Research

Common bacterial blight (CBB), caused by Xanthomonas axonopodis pv. phaseoli and Xanthomonas fuscans subsp. fuscans (Xff), is a worldwide disease of common bean (Phaseolus vulgaris L.). Longyundou 5, a Chinese cultivar in the Mesoamerican gene pool of common bean, displays resistance to the Xff strain XSC3-1. To identify the genetic mechanisms behind this resistance, we crossed Long 5 with a susceptible genotype to develop a mapping population of F2 plants. Plant resistance to CBB was identified at 14 and 21 days after inoculation with Xff strain XSC3-1. A major QTL at 14 and 21 days after inoculation …

Drought-Induced Leaf Proteome Changes In Switchgrass Seedlings, Zhujia Ye, Sasikiran Sangireddy, Ikenna Okekeogbu, Suping Zhou, Chih-Li Yu, Dafeng Hui, Kevin J. Howe, Tara Fish, Theodore W. Thannhauser

Agricultural and Environmental Sciences Faculty Research

Switchgrass (Panicum virgatum) is a perennial crop producing deep roots and thus highly tolerant to soil water deficit conditions. However, seedling establishment in the field is very susceptible to prolonged and periodic drought stress. In this study, a “sandwich” system simulating a gradual water deletion process was developed. Switchgrass seedlings were subjected to a 20-day gradual drought treatment process when soil water tension was increased to 0.05 MPa (moderate drought stress) and leaf physiological properties had expressed significant alteration. Drought-induced changes in leaf proteomes were identified using the isobaric tags for relative and absolute quantitation (iTRAQ) labeling method followed by …

Effect Of Bacteria Isolates In Powdery Mildew Control In Flowering Dogwoods (Cornus Florida L.), Margaret T. Mmbaga, Frank A. Mrema, Lucas Mackasmiel, Emily Rotich

Agricultural and Environmental Sciences Faculty Research

Five bacterial isolates collected from dogwood leaves were evaluated for powdery mildew control in shadehouse and greenhouse environments by using foliar sprays and/or root drenching. Two isolates displayed superior bioactivity and suppressed powdery mildew similar to conventional fungicide thiophanate methyl (Cleary’s 3336F®). The two bacteria disrupted powdery mildew spore germination and ruptured spore membranes causing spore lyses. Bacterial filtrates without bacterial cells were also effective in suppressing powdery mildew and disrupting spore germination and suggested the involvement of secondary metabolites. The two biocontrol agents (BCAs) colonized roots endophytically and promoted plant growth.

Responses Of Corn Physiology And Yield To Six Agricultural Practices Over Three Years In Middle Tennessee, Chih-Li Yu, Dafeng Hui, Qi Deng, Junming Wang, K. Chandra Reddy, Sam Dennis

Agricultural and Environmental Sciences Faculty Research

Different agricultural practices may have substantial impacts on crop physiology and yield. However, it is still not entirely clear how multiple agricultural practices such as tillage, biochar and different nutrient applications could influence corn physiology and yield. We conducted a three-year field experiment to study the responses of corn physiology, yield and soil respiration to six different agricultural practices. The six treatments included conventional tillage (CT) or no tillage (NT), in combination with nitrogen type (URAN or chicken litter) and application method, biochar, or denitrification inhibitor. A randomized complete block design was applied with six replications. Leaf photosynthetic rate, transpiration, …

Using Plant Volatile Traps To Estimate The Diversity Of Natural Enemy Communities In Orchard Ecosystems, Nicholas J. Mills, Vincent P. Jones, Callie C. Baker, Tawnee D. Melton, Shawn A. Steffan, Thomas R. Unruh, David R. Horton, Peter W. Shearer, Kaushalya G. Amarasekare, Eugene R. Milickzy

Agricultural and Environmental Sciences Faculty Research

In this study we used sticky traps baited with plant volatile lures to monitor the biodiversity of natural enemies in orchard ecosystems in the western U.S. We compared the diversity of predator genera from season total trap catches in 37 different orchards (apple, cherry, pear and walnut) over a two-year period (2010−2011) using standardized Hill number biodiversity indices and community similarity profiles. For a subset of 23 of these orchards we were also able to monitor the change in biodiversity of predator genera over the full growing season in the different orchard crops. A total of 37,854 individuals from 31 …

Biology, Ecology, And Management Of Nonnative Ambrosia Beetles (Coleoptera: Curculionidae: Scolytinae) In Ornamental Plant Nurseries, Christopher M. Ranger, Michael E. Reding, Peter B. Schultz, Jason B. Oliver, Steve D. Frank, Karla M. Addesso, Juang Hong Chong, Blair Sampson, Christopher Werle, Stanton Gill, Charles Krause

Agricultural and Environmental Sciences Faculty Research

Xylosandrus germanus (Blandford) and Xylosandrus crassiusculus (Motschulsky) (Coleoptera: Curculionidae: Scolytinae) are two of the most damaging nonnative ambrosia beetle pests in ornamental plant nurseries. Adult females tunnel into the stems and branches of host plants to create galleries with brood chambers. Hosts are infected with symbiotic Ambrosiella spp. fungi that serve as food for the larvae and adults. Plants can also become infected with secondary opportunistic pathogens, including Fusarium spp. Both X. germanus and X. crassiusculus have broad host ranges, and infestations can result in “toothpicks” of extruded chewed wood and sap flow associated with gallery entrances, canopy dieback, stem …

Effects Of Heat Shock On Photosynthetic Properties, Antioxidant Enzyme Activity, And Downy Mildew Of Cucumber (Cucumis Sativus L.), Xiaotao Ding, Yuping Jiang, Ting Hao, Haijun Jin, Hongmei Zhang, Lizhong He, Qiang Zhou, Danfeng Huang, Dafeng Hui, Jizhu Yu

Biology Faculty Research

Heat shock is considered an abiotic stress for plant growth, but the effects of heat shock on physiological responses of cucumber plant leaves with and without downy mildew disease are still not clear. In this study, cucumber seedlings were exposed to heat shock in greenhouses, and the responses of photosynthetic properties, carbohydrate metabolism, antioxidant enzyme activity, osmolytes, and disease severity index of leaves with or without the downy mildew disease were measured. Results showed that heat shock significantly decreased the net photosynthetic rate, actual photochemical efficiency, photochemical quenching coefficient, and starch content. Heat shock caused an increase in the stomatal …

From Planning To Execution To The Future: An Overview Of A Concerted Effort To Enhance Biological Control In Apple, Pear, And Walnut Orchards In The Western U.S., Vincent P. Jones, Nicholas J. Mills, Jay F. Brunner, David R. Horton, Elizabeth H. Beers, Thomas R. Unruh, Peter W. Shearer, Jessica R. Goldberger, Steven P. Castagnoli, Nadine Lehrer, Eugene R. Milickzy, Shawn A. Steffan, Kaushalya G. Amarasekare, Ute Chambers, Angela N. Gadino, R. Karina Gallardo, Wendy E. Jones

Agricultural and Environmental Sciences Faculty Research

We embarked on a large project designed to help enhance biological control in apple, pear and walnut orchards in the western U.S., where management programs were in the midst of a transition from older organo-phosphate insecticides to mating disruption and newer reduced-risk insecticides. A “pesticide replacement therapy” approach resulted in unstable management programs with unpredictable outbreaks of spider mites and aphids. Our project was designed to provide growers and pest managers with information on the effects of newer pesticide chemistries on a suite of representative natural enemies in both the laboratory and field, potential of new monitoring tools using herbivore-induced …

Genetic Dissection Of Icp-Detected Nutrient Accumulation In The Whole Seed Of Common Bean (Phaseolus Vulgaris L.), Matthew Wohlgemuth Blair, Xingbo Wu, Devendra Bhandari, Carolina Astudillo

Agricultural and Environmental Sciences Faculty Research

Nutrient transport to grain legume seeds is not well studied and can benefit from modern methods of elemental analysis including spectroscopic techniques. Some cations such as potassium (K) and magnesium (Mg) are needed for plant physiological purposes. Meanwhile, some minerals such as copper (Cu), iron (Fe), molybdenum (Mo), and zinc (Zn) are important micronutrients. Phosphorus (P) is rich in legumes, while sulfur (S) concentration is related to essential amino acids. In this research, the goal was to analyze a genetic mapping population of common bean (Phaseolus vulgaris L.) with inductively coupled plasma (ICP) spectrophotometry to determine concentrations of …

Hairy Canola (Brasssica Napus) Re-Visited: Down-Regulating Ttg1 In An Atgl3-Enhanced Hairy Leaf Background Improves Growth, Leaf Trichome Coverage, And Metabolite Gene Expression Diversity, Ushan I. Alahakoon, Ali Taheri, Naghabushana K. Nayidu, Delwin Epp, Min Yu, Isobel Parkin, Dwayne Hegedus, Peta Bonham-Smith, Margaret Y. Gruber

Agricultural and Environmental Sciences Faculty Research

Background

Through evolution, some plants have developed natural resistance to insects by having hairs (trichomes) on leaves and other tissues. The hairy trait has been neglected in Brassica breeding programs, which mainly focus on disease resistance, yield, and overall crop productivity. In Arabidopsis, a network of three classes of proteins consisting of TTG1 (a WD40 repeat protein), GL3 (a bHLH factor) and GL1 (a MYB transcription factor), activates trichome initiation and patterning. Introduction of a trichome regulatory gene AtGL3 from Arabidopsis into semi-glabrous Brassica napus resulted in hairy canola plants which showed tolerance to flea beetles and diamondback moths; however …